迭代法是用于求方程或方程组近似根的一种常用的算法设计方法。设方程为f(x) 0，用某种数学方法导出等价的形式x g(x)，然后按以下步骤执行：

（1） 选一个方程的近似根，赋给变量x0；

（2） 将x0的值保存于变量x1，然后计算g(x1)，并将结果存于变量x0；

（3） 当x0与x1的差的绝对值还小于指定的精度要求时，重复步骤（2）的计算。

若方程有根，并且用上述方法计算出来的近似根序列收敛，则按上述方法求得的x0就认为是方程的根。-Iteration is a commonly used method for finding the approximate roots of equations or equations. Let the equation be f (x)　 0, derive the equivalent form x　 g (x) by some mathematical method, and do the following:

(1) choose the approximate root of an equation, assigned to the variable x0

(2) the value of x0 stored in the variable x1, and then calculate g (x1), and the results stored in the variable x0

(3) When the absolute value of the difference between x0 and x1 is less than the specified accuracy requirement, the calculation of step (2) is repeated.

If the equation has roots and the approximate root sequence calculated by the above method converges, x0 obtained by the above method is considered to be the root of the equation